Technical Field
The present disclosure relates to a touch sensor and an organic light emitting display device including the touch sensor.
Description of the Related Art
Image display devices that output information on a screen are being developed into thinner, lighter-weight, portable and high-performance forms. Recently, an organic light emitting display device configured to display an image by controlling the amount of light emitted from an organic light emitting diode (OLED) has attracted significant attention.
The organic light emitting diode is a self-emitting device using a thin emission layer between electrodes and can be manufactured into a thin film. A general organic light emitting display device has a structure in which a pixel driving circuit and an organic light emitting diode are formed on a substrate. Further, the general organic light emitting display device displays an image when a light emitted from the organic light emitting diode passes through the substrate or a barrier layer.
The organic light emitting display device is implemented without a separate light source and thus can be easily implemented as a flexible display device that can be bent, folded, stretched or otherwise deformed in a desirable manner. In this case, flexible materials such as plastic, metal foil, and the like are used for the substrate of the organic light emitting display device. Generally, polyimide (PI) is employed for the substrate of the organic light emitting display device among various flexible materials.
Also, display devices having a touch input function are being widely used. A so-called touch screen panel (TSP) is a device configured to sense a user's input such as a touch or a gesture with respect to a display device. Touch screen panels are implemented in portable devices such as smart phones and tablet PCs and a large-sized display devices such as signage or displays in public facilities, smart TVs, and the like. Such touch screen panels can be classified into resistive, capacitive, optical, and electromagnetic (EM) touch screen panels according to their basic operation principles. Recently, the demand for touch screen panels capable of sensing different types of touch inputs have been increased. Accordingly, research on enhanced touch panels capable of more accurately measuring a position of a touch input and the force thereof is being actively conducted.